Once you find water, a major issue remains: Is it pure? Is it drinkable? And if not, how to make it drinkable?
You can make a water filler(过滤器)from a cone of birch bark(桦树皮). This cone is then filled with layers of sand, charcoal(木炭), grasses, and other materials. Grasses and sand help to trap suspended particles(悬浮颗粒). Charcoal helps to remove chemical impurities, but not bacteria. You may have to pass the water through the filter more than once, depending on the site of the filter and what it's made of. Generally speaking, the bigger the filler, and the more layers you have in it, the better.
The birch bark cone will need to have a fairy small hole in the bottom. The cone will have to be tied with cordage to keep it from opening up. Put a few stones in the very bottom, to help hold your filtering materials in place. Then pour in lavers of charcoal, grasses, sand, and possibly other materials that you feel will help to filter out suspended particles and perhaps even bacteria.
Once you have constructed the filter, simply pour impure water through the filer, catching it in another container at the bottom.
This is basically the "well" method of obtaining water. Dig a hole about 2 4 feet from a water source, such as a river. Allow the hole to fill with water. The water in the hole will likely be reasonably pure.
1. How do we get purer water?A.Bigger filter and less layers. | B.Smaller filler and more layers. |
C.Larger filter and more layers. | D.Smaller filter and less lavers. |
A.Killing bacteria. | B.Removing chemicals. |
C.Blocking water. | D.Keeping the materials balanced. |
A. | B. | C. | D. |
A.absorbing water | B.cleaning water | C.finding water | D.boiling water |
相似题推荐
Middle school is a fun time for young teens. You meet new people and go to parties. But many teenagers notice their grades descending in middle school. Classes get harder and it is tougher to keep up. Besides, going to parties takes up a lot of time. The following are some tips on how to improve your grades in middle school.
★Talk to your parents and see how they can help. Ask them for little things, like keeping the TV off for an hour while you study and do homework, or keeping you on task by checking once in a while to make sure you aren’t playing computer games. Parents have gone through school and they can help.
★Seek teachers’ advice as well. They have taught hundreds of students and know many different approaches to learning. See if they can meet with you twice a week after school to help you find out the best way for you to learn.
★Ask for extra homework. If your grade is becoming lower and you need a quick improvement, see if the teacher can give you any extra homework for you to do at home.
★Practice makes perfect. Do your homework every night. If you don’t have homework, review what you have learned for at least 10 minutes. If you are struggling in a class and the teacher doesn’t give homework often, consider asking some questions from the book once in a while to review. Sure, other students will think you are crazy, but if it helps, it doesn’t matter. If the problem lies beyond something you can control, such as a learning disability or problems at home, ask help from a teacher or parent.
★Have your own study area where you can study without being distracted. This study area should also improve your motivation of learning, so decorate it with things that will help you stay organized and not with things that will distract you.
1. What does the underlined word “descending” mean? (one word)2. According to Paragraph 3, why do you need to ask your teachers for advice? (no more than 15 words)
3. For what purpose do you ask for extra homework? (no more than 10 words)
4. How should you decorate your study area? (no more than 12 words)
5. Please give your opinion on how to improve grades in middle school. (no more than 20 words).
【推荐2】The Ways to Avoid Fighting with Your Mom
Life is a struggle, but if you have a bad relationship with your mother, you should cool your passion, because mother-children relationships are very important.
Don't give her the silent treatment.
If you think that the silent treatment will always help you achieve a desirable result, then you're mistaken.
Avoid deeply rude words.
If you're quarreling with your mother, you should be careful with what you say to her.
Don't draw other family members into a conflict.
Say that you have a terrible habit of drawing your brother and dad into conflict between you and your mother.
Lack of communication between mothers and children can create emotional obstacles and even cause frequent quarrels. When you finally find the reason, you'll be able to overcome misunderstanding in communication with your mother and bridge the generation gap in a quite short period of time.
A.Refuse to get crazy. |
B.Improve your communication. |
C.You shouldn't burst into tears in front of your mother. |
D.Sure, your mom will refuse to communicate with you as well. |
E.Here are some ways that will help you avoid fighting with your mother. |
F.You want them to support you and help you find a beneficial solution for each other. |
G.Sometimes your words can be either a perfect pain reliever or a terrible sharp sword. |
【推荐3】How to Help Your Teenager Decide on a Career
“What do you want to be when you grow up?” It used to be a cute question. But now that your child is a teen, they’re either sick of hearing it or frightened because they don’t have an answer. As a parent, helping your teenager choose a career is highly important.
Take the pressure off
Students leaving school often experience anxiety as they struggle to decide on a life plan. Some teens worry that they’ll disappoint their parents if they don’t take a direct path to a perfect job.
Lead by example
Help them identify their strengths
A key step in helping your teenager choose a career is aiding them to understand themselves.
If your teenager doesn’t have an idea of what they want to do after high school, it’s important to keep an open dialogue and gently encourage them.
A.It may be beneficial to visit a career advisor. |
B.That’s why we’ve put together this practical guide here. |
C.But the weight of the world doesn’t rest on their shoulders. |
D.Make it your responsibility to be a safe space for your teen. |
E.You’re the first and most important role model in your teen’s life. |
F.A great way to promote this is asking questions about their future. |
G.As their parent, you naturally know your teen and what areas they are good at. |
【推荐1】Animals can move from place to place, but plants cannot. When an animal is under attack, it can run away or fight back. Plants certainly cannot run away, and they lack teeth and claws. But plants can defend themselves by using both physical and chemical means.
Some plants have their own ways to keep animals away. For example, the leaves of the holly plant have sharp spines (刺) that discourage grass-eating animals. Holly leaves on lower branches have more spines than leaves on upper branches. This is because the lower leaves are easier for most animals to reach.
Some plants, such as the oak tree, have thick and hard leaves that are difficult for animals to eat. Some grasses may contain a sandy material; eating such grasses wears down the animal's teeth.
Many plants also have chemical defenses. Some plants produce chemicals that taste bitter or cause an unpleasant reaction. Some plants may fight against an attack by increasing the production of these chemicals. When a caterpillar (毛虫) bites a tobacco leaf, the leaf produces a chemical messenger. This messenger sends to the roots the information to produce more nicotine. The higher levels of nicotine discourage the caterpillar.
Many plants depend on both physical and chemical defenses. A certain plant in China, for instance, has prickly (多刺的) leaves, and each prickle contains poisonous venom (毒液). A single experience with this kind of plant will teach an animal to stay away from it in the future.
1. The holly plant has more spines on the lower leaves because most animals________.A.are not tall enough | B.like the lower leaves only |
C.are not clever enough | D.can get the lower leaves easily |
A.chemical means | B.physical means |
C.bitter chemicals | D.sandy materials |
A.Its leaves fight against the attack by physical means. |
B.Its roots send a messenger to discourage the caterpillar. |
C.Its roots increase the production of nicotine when it is attacked. |
D.Its leaves produce poisonous sand to drive the caterpillar away. |
A.Plants and Animals | B.How Plants Defend Themselves |
C.Attacks and Defenses | D.How Animals Eat Plant Leaves |
【推荐2】Body language is as important as the language itself. And if you think it means the same all around the world, you’ve got that all wrong. Gestures that mean something in one country don’t necessarily mean the same in another. As much as you need to learn a second language fluently, it’s also vital to get to know gestures in different cultures.
No matter how fluently you can speak Russian, we bet you don’t know a fun fact. While counting from one to five using fingers, people all over the world start counting with a ball-up fist. Starting from one, you uncurl(伸直) each of the fingers. Until you come to five, your hand is wide open. Everywhere worldwide, people count like this except in Russia. Instead of a ball-up fist, they start counting with a wide-open hand. So, when Russians start counting from one, they curl their fingers one by one. In the end, when they reach five, they get a ball-up fist.
What is the best way to learn Italian? Let’s be straight right away: without hand gesturing, it is impossible. So, if you are learning Italian, besides the language, you should learn their hand gestures as well. One of the worldwide-known Italian gestures is the pinecone. The pinecone gesture is formed when you bring all the tips of your fingers to one point. Then you move your wrist back and forth. The gesture is usually used when you have questions.
1. How might Russians express ten with hands?A.With two fists. | B.With two fingers. |
C.With two open hands. | D.With one finger and a fist. |
A.Happiness. | B.Confusion. | C.Appreciation. | D.Fear. |
A.Tips on learning Italian. |
B.Ways of communication. |
C.Meanings of hand gestures. |
D.Techniques of counting numbers. |
【推荐3】Teenagers who start the school early are likely to weigh slightly more than those who start later. That’s the finding of a new study of nearly 30,000 Canadians between the ages of 10 and 18.
Getting too little sleep can put kids at risk for a number of problems. Sleepy teens are more likely to be overweight, to have trouble concentrating and to struggle in school. Genevieve Gariepy, who works at Mcgill University in Montreal, Canada, wanted to know how earlier school start times might be connected with weight.
“Overweight in teenagers is a big problem in North America,” she says. The number of overweight kids has grown over the past 30 years. So Gariepy decided to home in on the impact (影响) of school start times.
Her team collected start times for 362 Canadian schools. Then they asked students at those schools to give their height and weight. In all, they collected data from nearly 30,000 10 to 18-year-olds. Among 6th-to 10th-graders, those who started school earlier were likely to be slightly heavier for their height. Every 10-minute delay in school start time was connected, on average, with a lightly lower weight among students who were the same sex, age and height. However, the difference is slight. Healthy eating and getting enough exercise will play a bigger role in keeping a healthy weight.
Because the study compared kids who already started school at different times of day, it’s not clear that changing school start time would help heavier kids lose weight. To know for sure, researchers would want to compare the same kids before and after changing to a later school start time.
Still, the study is a good start, says Cora Collette Bruener, a doctor at Seattle Children’s Hospital in Washington. The findings add to a growing pile of evidence that later school start time might be better for teen health, she says.
1. What is the finding of the new study?A.More and more teens are growing overweight. |
B.Healthy diets and enough exercise help reduce weight. |
C.Teens who start school earlier are a little overweight. |
D.Teens who start school earlier do not perform well. |
A.reduce | B.focus on |
C.move to | D.judge |
A.By recording the teen’s weight. | B.By checking the teen’s physical health. |
C.By comparing different sets of data. | D.By measuring the teen’s height. |
A.It has inspiring value. | B.It lacks further support. |
C.It needs improving. | D.It is well designed. |
A.discuss when schools should start. |
B.inform the finding of a recent study. |
C.warn parents to take good care of kids. |
D.call on school leaders to change schools’ schedules. |
【推荐1】Sales of Apple’s new iPhone 11 in China began on Friday, but were met with a cooler reception from consumers than in previous years. Unlike in previous years, no long lines were seen outside Chinese shops on Friday for the new iPhone, and the product release only made the headlines in a few media outlets.
Huawei unveiled its Mate 30 smartphone series on Thursday night. Its new devices have won consumers’ hearts at home and abroad. Many compared it with Apple’s new iPhone 11, saying that beats the new iPhone in terms of innovation and quality. One customer surnamed Zhao, an IT specialist who pre-ordered a Mate 30 Pro on Friday, said that he chose Mate 30 without hesitation. Zhao said, “It’s obvious that Huawei’s new phone with its advanced 5G mode would lead the future global telecommunications market, and its new innovative features in gesture and side control attracted my attention, too.”
In contrast with iPhone 11’s lukewarm sales, Chinese netizens have engaged in discussions on Mate 30 and Mate 30 Pro. An online poll on the Mate 30 and iPhone 11 on Weibo on Friday showed that more than 60 percent of netizens chose the Mate 30, while less than 20 percent chose the iPhone 11. Many chose Huawei not out of patriotism but for its technology.
Overseas consumers also engaged in vigorous discussions on Huawei’s new flagship devices on technology sites and social media platforms. On Twitter, many netizens said “nice”, “best phone ever” and “my favorite one” on Huawei’s Twitter account. Some netizens in countries like the UK, the Netherlands and Argentina asked when Huawei’s new devices would be released in their countries.
1. How did customers react to Apple’s new product?A.They thought it was cool to use it. | B.They stood in long lines to purchase it. |
C.They were less interested in it than former years. | D.They thought its quality was worse than before. |
A.The price and the weight. | B.The quality and innovation. |
C.The appearance and the speed. | D.The service life and function. |
A.Store. | B.Exam. | C.Account. | D.Vote. |
A.A New Era—5G | B.Huawei Is Better than Apple |
C.Huawei’s Mate 30 Defeats iPhone 11 | D.Apple’s New iPhone 11 |
【推荐2】Many people say that looking back is meaningless because it can neither change the past nor bring it back to life, but I disagree as I enjoy the sense of nostalgia (怀旧感), which can remind me of how life used to be when I was younger. Don't get me wrong, however. I'm not one of those who love to talk ad nauseam about "the good old days".
As we know, there are moments when the past springs into the present. It's often a smell that will remind me of a particular place or person. A perfume, the scent of a flower, baking bread, bonfires...they all create an instant picture. For me it is the smell of a freshly painted room. We moved so many times when I was younger and each time the first thing my parents would do is decorate our bedrooms. The windows would be kept open to get rid of the smell of the paint but it would always linger on (留存) for days. Even today it fills me with a sense of new beginnings.
Those memories are fleeting (飞逝). But when I visit the seaside resort where we used to spend many of our family holidays, I can replay entire days in my head. I can vividly remember the weather, the salty smell of the sea, our dogs playing in the water, an ice cream and that feeling of exhaustion after a day in the fresh air.
Although having many photos of those days, I rarely look at them as I prefer to allow my memory to create the pictures. Today we can so easily capture (捕捉) the present with phones and cameras, upload the images and share that moment with our friends online. But, for me, that somehow takes away the unique connection.
1. The underlined part "ad nauseam" in Paragraph 1 may be replaced by .A.wisely | B.endlessly |
C.simply | D.honestly |
A.a new start | B.a new home |
C.another move | D.another holiday |
A.A magazine. | B.A guidebook. |
C.A book review. | D.A science fiction. |
A.Dull. | B.Bitter. |
C.Unforgettable. | D.Regretful. |
【推荐3】Israeli researchers say they have invented a reusable face mask that can kill the coronavirus with heat by drawing power from a mobile phone charger.
The disinfecting(消毒)process takes about half an hour-and users should not wear the mask while it is plugged in, said Professor Yair Ein-Eli, who led the research team at Technion University in Haifa. TI new mask has a USB port that connects to a power source such as a standard cellphone charger that heats an inner layer of carbon fibres to 70 degrees Celsius, high enough to kill viruses.
Ein-Eli said disposable masks, in high demand globally during the health crisis, were not economically or environmentally friendly. “This is our solution,” he said.
Professor Allon Moses, an infectious diseases expert at Jerusalem’s Hadassah Medical Center, said there was “no question” that a half hour’s exposure to 70-degree heat would kill the coronavirus. But he cautioned that repeated heating could “damage the masks paper or fabric and spoil its ability to protect from diseases in the future.”
During testing, the prototype was exposed to 20 heating cycles, each for half an hour, with no damage on durability, Ein-Eli said. “We can guarantee it up to a few dozen cycles, without any risk,” he added.
The prototype looks like a standard N95 face mask, with a valve(阀) at the front and bands to hold it in place around the head. The researchers submitted a patent for the mask in the United States in late March and say they are discussing commercializing the product with the private sector. It will likely sell at a $ l premium over the price of a typical disposable face mask, the researchers say.
1. How long does the disinfecting process usually take?A.Around 20 minutes. | B.around 30 minutes. |
C.Around 60 minutes. | D.Around 70 minutes. |
A.To kill viruses thoroughly. | B.To spread a novel idea. |
C.To replace the traditional ones. | D.To make reusable and friendly ones. |
A.The reusable face masks were unhealthy. |
B.70-degree heat would hurt people in a way. |
C.The cost of reusable face masks may be high. |
D.The function of mask to prevent diseases was ruined. |
A.Fine. | B.Extra. | C.Currency. | D.Face value. |
【推荐1】When Joy Warren’s husband of 50 years passed away, her confidence took a knock. Meeting new people and joining in again socially was a frightening thought. Fortunately, just doors away were friendly neighbours Janet and Michael Porter, who knocked on her door and invited her to join them at a local friendship group event.
And it all started from there, explained Joy, 75, “I’ve never been the type to sit still, so despite the fact that I was still sad for Graham, I knew I had to get out and socialise again, but it was difficult to know where to start. That knock on the door was the encouragement I needed.”
From that first neighbourly invitation, Janet and Michael have been there for Joy, inviting her along to take part in regular Oddfellows social events.
She continued, “They made sure I was never alone for too long, and if I didn’t fancy coming with them, there was never any pressure, just a gentle reminder that they were always there. I joined them at all sorts of group meetings and events, from visiting the local dogs’ home to having a catch up at the monthly coffee morning. I signed up to the Oddfellows as a result of the wonderful new friends I made there.”
Joy also found that after losing her husband, she was alone in making decisions about her home and finances, often struggling with what needed to be done.
She added, “Graham used to take care of all that, so it’s been tough for me to figure out what the right thing to do is sometimes. The Oddfellows was a huge help with this as they have a Citizen’s Advice Line for members, which has got me through some complicated times.”
1. How did Joy Warren feel when Graham left her?A.She was too sad to see anyone. |
B.She couldn’t wait to meet new friends. |
C.She had no idea how to mix with others. |
D.She felt it easy to handle daily affairs by herself. |
A.Paying visits to the local nursing home. |
B.Making decisions about what needed to be done. |
C.Having a get-together at the weekly coffee morning. |
D.Participating in Oddfellows activities on a regular basis. |
A.She worked them out on her own. |
B.She relied on her children for advice. |
C.She ignored them and escaped from reality. |
D.She sought help from Oddfellows’ Citizen’s Advice Line. |
A.Oddfellows, Colorful Social Events |
B.Hanging Out With Friendly Neighbors |
C.A Neighborly Knock To Cure Loneliness |
D.A Friendly Invitation From Lovely Neighbors |
【推荐2】Like many other students beginning graduate school, I was quickly charged with responsibilities and had to find time for studying by letting go of many other things I valued. Letting go of football and the violin was, however, self-defeating: it might have brought me more time in the short term, but spending that extra time on work only’ made me more stressed and less productive.
Towards the end of the MSC (Master of Science program) started to lose my motivation and curiosity for science and research, as well as my creativity. Spending so much time and energy in the laboratory, and focusing all my attention on my thesis and courses, made me feel down and almost totally uninterested in my field - not to mention short-tempered and oversensitive in my personal communications.
Over time, I learnt from these experiences. When I started my PhD, I focused on balancing academic success with personal time-off, and made personal happiness a priority (首要事情) in my weekly schedule. My mentor (导师) and I discussed my work-life balance early in my program, and we arrange our lab responsibilities accordingly.
I set boundaries for myself in new ways: ‘rather than doing lab work all weekend, I’d play football or the violin, or visit loved ones, before allowing myself to work fora few hours.
This was hard at first: I worried that it would affect my standing with my peers, and superiors, but I had learnt from experiences that an overloaded schedule can drain (使疲劳) you so much that you become unfocused and start making mistakes or forgetting important details.
Since establishing a better work-life balance, I’ve been doing well in graduate school. Outside the lab, I’ve been able to take up a few leadership positions at my university because I’m not as stressed with my work. I serve as our department’s student councilor and I am also vice-president academic in the Health Sciences Graduate Students’ Association. My advice is this: a healthy work-life balance isn’t a luxury; it’s a key part of success in graduate programs.
1. What is the author’s problem?A.He must study hard to graduate. |
B.He must give up his hobby for study, |
C.He didn’t know how to study more effectively. |
D.He didn’t know how to deal with pressure. |
A.the challenges of an MSC program |
B.the consequences of giving up hobbies |
C.the benefits of focusing on schoolwork |
D.the importance of balancing study and hobbies |
A.asks his peers for help |
B.seeks to reduce his lab duties |
C.puts his hobbies first more often |
D.avoids schoolwork at weekends at all |
A.tends to put things on hold |
B.tends to lose the attention to details |
C.will lose his patience with his academic work |
D.will make a new schedule accordingly |
A.It’s never too late to make a change in the university. |
B.It’s easy to be work-life balanced in our lives. |
C.Multi-tasking has many advantages in the university. |
D.Work-life balance is necessary in the university. |
【推荐3】When it comes to medical care, many patients and doctors believe “more is better.” But what they do not realize is that overtreatment—too many scans, too many blood tests, too many procedures—may bring harm. Sometimes a test leads you down a path to more and more testing, some of which may be invasive, or to treatment for things that should be left alone.
Terrence Power, for example, complained that after his wife learned she had Wegener's disease, an uncommon disorder of the immune system, they found it difficult to refuse testing recommended by her doctor. The doctor insisted on office visits every three weeks, even when she was feeling well. He frequently ordered blood tests and X-rays, and repeatedly referred her to specialists for even minor complaints. Even when tests came back negative, more were ordered, and she was hospitalized as prevention when she developed a cold. She had as many as 25 doctor visits during one six-month period. The couple was spending about $30,000 a year for her care.
After several years of physical suffering and near financial ruin from the medical costs, the couple began questioning the treatment after discussing with other patients in online support groups. “It's a really hard thing to determine when they've crossed the line,” Mr. Power said. “You think she's getting the best care in the world, but after a while you start to wonder: What is the purpose?” Mr. Power then spoke with his own primary care doctor, who advised him to find a new specialist to oversee Mrs. Power's care. Under the new doctor's care, the regular testing stopped and Mrs. Power's condition stabilized. Now she sees the doctor only four or five times a year.
1. What is the main idea of this passage?A.Treatments do not always cause harmful side effects. |
B.Patients tend to believe more testing is better treatment. |
C.Too much medical care may not be beneficial to patients. |
D.Doctors generally recommend office visits that are necessary. |
A.She had to be hospitalized for three weeks whenever she had a cold. |
B.When test results showed she was fine, her doctor still ordered more tests. |
C.She did not have any insurance, so she became penniless because of her illness. |
D.Her doctor asked her to consult other specialists due to her constant complaints. |
A.Doctors. | B.Other patients. |
C.Mr. and Mrs. Power. | D.The online support groups. |
A.Mrs. Power's condition getting worse. | B.The results of her blood tests. |
C.Knowing about other patients' treatment. | D.The advice from Mr. Power's doctor. |